天然气工业2025，Vol.45Issue(9)：47-58,12.DOI:10.3787/j.issn.1000-0976.2025.09.004
鄂尔多斯盆地致密砂岩气藏CO2-EGR关键技术:实验到矿场
Key technologies for CO2-EGR of tight sandstone gas reservoirs in the Ordos Basin:From experimental study to field application
摘要
Abstract
Under the background of dual carbon,CO2-enhanced gas recovery(CO2-EGR)is an effective technology for reducing greenhouse gas emissions while enhancing gas recovery.At present,however,the CO2-EGR technology for tight sandstone gas reservoirs face the challenges such as unclear displacement mechanisms,difficult quantification of carbon storage potential and incomplete area selection criteria,which restrict its large-scale popularization and application.Taking the EGR and carbon storage potential evaluation of tight sandstone gas reservoir CO2-EGR in the Ordos Basin as the research object,this paper researches and develops four key technologies and methods for the CO2-EGR of tight sandstone gas reservoirs,i.e.,physical simulation experimental method,recovery factor prediction technology,feasibility evaluation technology,and area selection evaluation technology,and systematically demonstrates the technical feasibility of tight sandstone gas reservoir CO2-EGR.The following results are obtained.First,the application of CO2-EGR technology to tight sandstone gas reservoirs can significantly improve the recovery rate of CH4.Transforming to CO2 flooding after core depletion development to the abandonment pressure of 7.5 MPa can improve the gas recovery by 22.2%,with a corresponding CO2 storage reaching 0.16 PV(pore volume).Second,the incremental recovery factor by CO2-EGR in tight sandstone gas reservoirs is related to the factors such as the pressure drop sweep efficiency of depletion development,pressure depletion efficiency,CO2 sweep efficiency,and CO2 displacement efficiency.When the mole fraction of CO2 at the outlet reaches 20%,the average CO2 displacement efficiency can reach 91.5%.Third,the optimal injection-production well spacing for CO2-EGR in tight sandstone gas reservoirs is 300-350 m,the optimal pressure for transforming to CO2 flooding is 7.5 MPa,the optimal injection pressure is 12.5 MPa,and the optimal moment for well shut-in occurs when the mole fraction of CO2 in the produced gas reaches 20%.It is estimated that the CO2-EGR in the X test area will increase the gas recovery factor by approximately 5.1%.Fourth,it is predicted that the application of CO2-EGR technology to the tight sandstone gas reservoirs in the Ordos Basin will increase natural gas production by 1 100×108 m3 and achieve CO2 storage potential of about 3.8×108 t.In conclusion,the research results support the transformation of CO2-EGR technology for tight sandstone gas reservoirs from experimental study to field application,which can effectively enhance gas recovery.With a complete injection-production well pattern and a reasonable injection-production system,CO2-EGR technology can increase the recovery factor of tight sandstone gas reservoirs by over 10%,which indicates its promising prospect of popularization and application.关键词
鄂尔多斯盆地/致密砂岩气藏/CO2-EGR/物理模拟实验/采收率预测技术/可行性评价技术/选区评价技术Key words
Ordos Basin/Tight sandstone gas reservoir/CO2-EGR/Physical simulation experiment/Recovery factor prediction technology/Feasibility evaluation technology/Area selection evaluation technology分类
能源科技引用本文复制引用
位云生,程刚,郭建林,曹正林,叶礼友,郭智,闫海军,王军磊,韩江晨..鄂尔多斯盆地致密砂岩气藏CO2-EGR关键技术:实验到矿场[J].天然气工业,2025,45(9):47-58,12.基金项目
中国石油天然气股份有限公司基础性前瞻性项目"气藏采收率标定方法与复杂气藏提高采收率新技术研究"(编号:2024DJ86). （编号:2024DJ86）
